During the winter months, it is common to see "sweat" or condensation on windows. Beyond being a nuisance, this condition can lead to mold...

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During the winter months, it is common to see “sweat” or condensation on windows. Beyond being a nuisance, this condition can lead to mold, rot and a musty odor throughout your home.

This excessive moisture is water vapor in the air turning into liquid water. It’s the same condition that occurs when a cold can of soda is removed from a refrigerator and exposed to room temperature — beads of moisture collect on the outside of the can to form a layer of condensation.

Many modern energy-efficient windows have features built in to keep the temperature of the glass as warm as possible and thus reduce condensation.

However, there is no such thing as a condensation-free window in high-humidity conditions. Controlling the amount of moisture in your home is the most effective action you can take to avoid condensation.

Here are a few ways to dry out sweating windows:

Open window blinds during the day. This allows sunlight in and will warm interior air to create natural air currents. The improved circulation results in a more-even temperature.

Use ventilation fans in bathrooms, kitchens and laundry rooms to remove excess moisture in the air.

Leave the fans on while bathing, cooking or doing laundry and for a period afterward to fully remove excess moisture.

Use a ceiling fan. In winter, run the fan in the reverse direction at a low to moderate speed.

The blades will push air upward toward the ceiling and down across walls and windows. This air movement will make for even heating and will dry most windows of condensation.

Air out your home frequently by opening doors and windows.

Reduce the number of indoor house plants, as plants increase humidity levels. If you have a terrarium, you know that the inside surface of the envelope is covered with condensation. That’s no accident — plants and damp soil increase humidity. If you have sweaty windows and lots of houseplants, you may need to thin out some of the plants to clear the windows.

Use a dehumidifier to remove excess humidity from the air. A dehumidifier is essentially an air-conditioner that has hot and cold coils in the same container. A fan draws humid air over the cold coil of the air-conditioner to condense moisture, which then drips into a collection container. Dry air passes over the hot coil to restore it to its original temperature.

For best indoor comfort and health, a relative humidity of about 45 percent is ideal. You can track your home’s humidity with an inexpensive hygrometer.